Tetraphenylimidodiphosphinate Ligand Research Articles

Synthesis, photoluminescence and electroluminescence of one iridium complex with 2-(2,4-difluorophenyl)-4-(trifluoromethyl)pyrimidine and tetraphenylimidodiphosphinate ligands

Using 2-(2,4-difluorophenyl)-4-(trifluoromethyl)pyrimidine as main ligand and tetraphenylimidodiphosphinate as ancillary ligand, one iridium complex was synthesized. This complex shows a green emission peaking at 543 nm with a quantum efficiency yield as 48% in deareated CH2Cl2 solution. It also has good thermal stability with a decomposition temperature of 351 °C. Using this material as emitter, the organic light-emitting diode shows good performances with a maximum luminance 42 898 cd/m2, a maximum current efficiency up to 54.29 cd/A with low efficiency roll-off. At the luminance of 5000 and 10 000 cd/m2, the current efficiencies are still kept at 46.70 and 40.63 cd/A, respectively.

Tetraphenylimidodiphosphinate ligand as potent complexation agent for ternary photoluminescent lanthanide complexes

Tetraphenylimidodiphosphinate ligand is considered as “inorganic” analogue of 1,3-diketonates, and forms neutral, highly photoluminescent ternary complexes with Eu(III), Tb(III), Dy(III), and Sm(III) involving three derivatives of 1,10-phenanthroline as auxillary ligands, complementing the coordination sphere around the lanthanide ions. The influence of these coligands were studied in the solid-state emission spectra, indicating high impact on the photoluminescence of ternary complexes.

Photoluminescence and electroluminescence of four platinum complexes with trifluoromethyl-substituted 2-phenylpyridine and tetraphenylimidodiphosphinate ligands

Four cyclometalated platinum complexes with trifluoromethyl-substituted 2-phenylpyridine at different positions on its phenyl group as the main ligands and tetraphenylimidodiphosphinate as the ancillary ligand, Pt1-Pt4 (Pt1 is a trifluoromethyl-free complex), were prepared, and their X-ray crystallography, photoluminescence, thermal stability, electrochemical analyses, theoretical calculation and EL performances were investigated. The positions of trifluoromethyl groups on the phenyl ring affected the emission spectra of platinum complexes greatly, and their corresponding emission peaks at 504/534, 512/545, 495/526 and 510/542 nm were observed at room temperature, respectively. Constructed with complexes Pt1-Pt4 as the emitters, respectively, the organic light-emitting diodes (OLEDs) with double light emitting layers structure of ITO/TAPC (1,1-bis[4-(di-p-tolylamino)phenyl]cyclohexane, 40 nm /Pt complexes (5 wt%): TCTA (4,4′,4″-tri(9-carbazoyl)-triphenylamine, 10 nm /Pt complexes (5 wt%): 2,6DCzPPy (2,6-bis(3-(carbazol-9-yl)phenyl)pyridine, 10 nm/TmPyPB (1,3,5-tri(m-pyrid-3-yl-phenyl)benzene, 40 nm)/LiF (1 nm)/Al (100 nm) showed good performances. Particularly, device G2 based on 2-trifluoromethyl-substituted complex Pt2 obtained a maximum luminance of 39196 cd m-2, a maximum current efficiency of 40.1 cd A−1 and a maximum power efficiency of 31.0 lm W−1, respectively, with low efficiency roll-off. The results suggested that these complexes Pt1-Pt4 would have potential applications in efficient OLEDs.

Green organic light-emitting devices with external quantum efficiency up to nearly 30% based on an iridium complex with a tetraphenylimidodiphosphinate ligand

High performance green electroluminescent device with maximum brightness, current efficiency, power efficiency and external quantum efficiency (EQE) up to 113 610 cd m−2, 112.30 cd A−1, 97.95 lm W−1 and 29.4%, was realized.

Dramatic improvement in photostability of luminescent Eu(III) complexes with tetraphenylimidodiphosphinate ligand

In this paper, we synthesized and characterized a new Eu(III) tetraphenylimidodiphosphinate complex with dimethyl sulfoxide (DMSO) as co-ligand. Moreover, we compared the photostability of a series of Eu(III) complexes containing tetraphenylimidodiphosphinate ligands, Eu(tpip)3, Eu(tpip)3Phen, Eu(tpip)3DMSO, with their analogs of 1,3-dibenzoylmethanate, Eu(dbm)3∙2H2O, Eu(dbm)3Phen, Eu(dbm)3(DMSO)2. We found that the photostability of the luminescent Eu(III) complexes was significantly improved upon substitution of the 1,3-diketones with tetraphenylimidodiphosphinate ligands.

Theoretical study on the electronic structures and optical properties of blue-green and blue phosphorescent iridium(III) complexes with tetraphenylimidodiphosphinate ligand

The electronic structures and photophysical properties of five iridium(III) complexes Ir(tfmppy)2(tpip) (1), Ir(dfppy)2(tpip) (2), Ir(afCNppy)2(tpip) (3), Ir(CNpyN3)2(tpip) (4), and Ir(2fphpta)2(tpip) (5) [where tfmppy = 4-trifluoromethylphenylpyridine; dfppy =4,6-difluorophenylpyridine; afCNppy = 6-fluoro-4-octyloxy-5-cyano-phenylpyridine; CNpyN3 = 2-(4-cyano-phenyl)-[1,2,3]-triazole; 2fphpta=2-(2,6-difluoro-phenyl-[1,2,4]-triazol-3-yl)-pyridine; tpip=tetraphenylimido-diphosphinate] have been investigated by using density functional theory (DFT) methods and time-dependent DFT ones, aiming at elucidating the influences of different substituents and cyclometalated ligands on the emission properties and quantum yield. The calculated results revealed that the different substituents in 1-3 have a great influence on the energy levels, in particular highest occupied molecular orbital. Meanwhile, we have also get a further insight into the reason for different phosphorescence quantum yields of the studied complexes. The higher quantum yield (Φ) reported for 1 was found to be closely related to both its smaller S1–T1 splitting energy ( ) and larger transition electric dipole moment ( ) upon the S0 → S1 transition. Complex 5 is expected to be a potential candidate for blue-emitting material with good organic light-emitting diodes performances. We propose that the optical properties of this class of materials can be tuned by the modifications of the cyclometalated ligands. © 2013 Wiley Periodicals, Inc.

Density functional theory and time‐dependent density functional theory study on a series of iridium complexes with tetraphenylimidodiphosphinate ligand

A series of heteroleptic cyclometalated Ir(III) complexes for organic light‐emitting diodes (OLEDs) application have been investigated theoretically to explore their electronic structures and spectroscopic properties. The geometries, the electronic structures, the lowest‐lying singlet absorptions and triplet emissions of Ir(dfppy)2(tpip), Ir(tfmppy)2(tpip), and theoretically designed models of Ir(ppy)2(tpip) were investigated with the density functional theory (DFT)‐based approaches, where ppy = 2‐phenylpyridine, dfppy = 4,6‐difluorophenylpyridine, tfmppy = 4‐trifluoromethylphenylpyridine, and tpip = tetraphenylimidodiphosphinate. Their structures in the ground and their excited states have been optimized at the DFT/Becke 3‐parameter Lee Yang Parr (B3LYP)/Los Alamos National Laboratory 2‐double‐z (LANL2DZ) and time‐dependent DFT/B3LYP/LANL2DZ levels, and the lowest absorptions and emissions were evaluated at B3LYP and M062X level of theory, respectively. Furthermore, the energy transfer mechanism together with the advantage of low efficiency roll‐off for these complexes also can be analyzed here. Copyright © 2013 John Wiley & Sons, Ltd.

Theoretical Studies on the Electronic Structures and Spectral Properties of Two Iridium(III) Complexes with Tetraphenylimidodiphosphinate Ligand

The geometrical structures, electronic structures, and spectral properties of two Ir(III) complexes with tetraphenylimidodiphosphinate ligand were investigated theoretically. The ground and the lowest lying triplet excited states were fully optimized at the B3LYP/LANL2DZ. TDDFT/PCM calculations have been employed to predict the absorption and emission spectra starting from the ground and excited state geometries, respectively. The lowest lying absorptions were calculated to be at 436 and 405 nm for the two Ir(III) complexes, respectively, and they have the transition configuration of HOMO → LUMO. The lowest lying transitions can be assigned as metal/ligand-to-ligand charge transfer (MLCT/LLCT) character for the two Ir(III) complexes. Ionization potentials (IP) and electron affinities (EA) were calculated to evaluate the injection abilities of holes and electrons. The theoretical results can be expected to provide valuable information to design new OLED materials.

Highly Efficient Green and Blue‐Green Phosphorescent OLEDs Based on Iridium Complexes with the Tetraphenylimidodiphosphinate Ligand

Two novel bis-cyclometalated iridium complexes are successfully applied in organic light-emitting diodes (OLEDs). Because of their better carrier transport ability and shorter excited stated lifetimes, good electroluminescence performances of the complexes are observed.

Ca[(Ph2PO)2N]2·nTHF, an α-hydroperoxidation promoter of coordinated THF molecules

Ca[(Ph2PO)2N]2·nTHF (2) was obtained by direct synthesis from tetraphenylimidodiphosphinic acid and Ca° in THF. X-ray quality single crystals of Ca2[(Ph2PO)2N]4·H2O (3) and Ca[(Ph2PO)2N]2·2C4H8O3 (4) were obtained upon crystallization of 2 under different conditions. The solid-state structure of 3 reveals a Ca2O3 core in which the two hexacoordinated calcium metals are linked together by three μ-oxygen atoms from three independent tetraphenylimidodiphosphinate ligands. Compound 4 is a monomeric octahedral complex bearing two tetraphenylimidodiphosphinate ligands in the equatorial plane and two α-hydroperoxidated THF molecules, formed in situ, in the axial positions. Compound 4 represents the first example of a metal center exhibiting this type of hydroperoxidation behavior.

Complexation of the uranyl ion (UO 2) 2+ with a tetraphenylimidodiphosphinate ligand: the first trinuclear uranyl complex comprising a double μ 2-oxo (UO 2) bridge

Reaction of K[(OPPh 2) 2N] with UO 2(NO 2) 2 · 6H 2O resulted in the formation of compound [UO 2[(OPPh 2) 2N] 2] 3 ( 1). Single-crystal diffraction analysis of 1 reveals an elaborated and unique trinuclear uranyl compound, where the central UO 2 moiety exhibits Lewis basic properties through an equatorial U⋯O U O⋯U bridging towards two outer uranyl units comprised in a six-membered ring array. The central and outer UO 2 groups are also bridged by means of four eight-membered rings containing the ancillary ligand. The overall morphology of this compound may be regarded as a linear U 3O 2 core engaging two different types of environments for the uranium atoms.

Complexes of In(III) with tetraphenylimidodiphosphinate ligands

We report the synthesis and characterization of the inorganic heterocyclic complexes In(OPPh2NPPh2O)3 and In(SPPh2NPPh2S)3. The structure of the sulfur derivative was determined by X-ray methods. The complex presents a distorted Oh symmetry and it is compared with the Bi(III) analog. The31P-NMR data and the X-ray structural determination suggest that the bulky ligands are responsible for the geometrical features in these complexes and therefore, for the Bi(III) analogs perhaps the lone pair does not play an important role in the structure.

Complexes of Bi(III) with tetraphenylimidodiphosphinate ligands

Complexes of Bi(III) with tetraphenylimidodiphosphinate ligands